A variety of commands can be entered while in command mode to set up vi just how you like it. Depending on your editor, you can enable
features to make programming easier (like syntax hilighting, auto-indenting, and more),
set up macros to automake tasks, enable textual substitutions, and more.

Almost all of these commands can be put into a configuration file in your home
directory. elvis expects a .exrc file,
while vim expects a .vimrc file. Most
of the setup commands that can be entered in command mode can be placed in the
configuration file. This includes setup information, textual substitutions, macros, and
more.

Discussing all these options and the differences between the editors is quite an
involved subject. For more information, check out the man page or web site for your
preferred vi editor. Some editors (like vim) have extensive help within the editor that can be accessed with
the :help command, or something similar. You can also check out the
O'Reilly book Learning the vi Editor by
Lamb and Robbins.

Many common programs in Linux will load up a text file in vi
by default. For example, editing your crontabs will start up vi
by default. If you do not like vi and would like another editor
to be started instead, all you need to do is set the VISUAL
environment variable to the editor you prefer. For information on setting environment
variables, see the section called Environment Variables in Chapter 8. If you want to make
sure that your editor will be the default every time you login, add the VISUAL setting to
your .bash_profile or .bashrc
files.